From: The IESG To: IETF-Announce Message-Id: Date: Thu, 16 Jun 2005 13:52:08 -0400 Cc: mmusic chair , Internet Architecture Board , mmusic mailing list , mmusic chair , RFC Editor Subject: [MMUSIC] Protocol Action: 'The SDP (Session Description Protocol) Label Attribute' to Proposed Standard The IESG has approved the following document: - 'The SDP (Session Description Protocol) Label Attribute ' as a Proposed Standard This document is the product of the Multiparty Multimedia Session Control Working Group. The IESG contact persons are Allison Mankin and Jon Peterson. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-mmusic-sdp-media-label-01.txt Technical Summary This specification defines a new Session Description Protocol (SDP) media-level attribute: "label". The "label" attribute carries a pointer to a media stream in the context of an arbitrary network application that uses SDP. The sender of the SDP document can attach the "label" attribute to a particular media stream or streams. The application can then use the provided pointer to refer to each or all of the media in its particular context. SDP is a body or document used by other protocols. It is left to the using applications to manage the "label" attribute. However an important user of the attribute is identified, the XCON framework. The SIP conferencing package, in review at the same time as this specification, is another important using protocol. Working Group Summary The document carefully reviews why other SDP attributes or functionality which to provide this labeling function were not chosen. The working group had raised each of the alternatives and discussed the points through to consensus. Before working group last call, there was a thorough document review by Magnus Westerlund, and the specification revised for small issues from that was supported for advancement. Protocol Quality Allison Mankin has reviewed the specification for the IESG. Note(s) to the RFC Editor Replace normative reference to RFC 2234 with normative reference to draft-crocker-abnf-rfc2234bis-00.txt [DS in RFC Editor Queue] Section 1. Add a sentence at the end of the second paragraph. OLD: [...] media stream's role in the conference) about it. NEW: [...] media stream's role in the conference) about it. The SIP Event Package for Conference State [Informative refence to draft-ietf-sipping-conference-package] defines and uses a concrete format for such external documents. Section 4: extend the ABNF as follows: OLD: Its formatting in SDP is described by the following BNF [2]: label-attribute = "a=label:" pointer pointer = token NEW: Its formatting in SDP is described by the following ABNF [normative reference to draft-crocker-abnf-rfc2234bis-00.txt]: label-attribute = "a=label:" pointer pointer = token token-char = %x21 / %x23-27 / %x2A-2B / %x2D-2E / %x30-39 / %x41-5A / %x5E-7E token = 1*(token-char) The token-char and token elements are defined in [give a Normative reference to draft-ietf-mmusic-sdp-new-24.txt] but included here to provide support for the implementor of this SDP feature. Section 6: addition of an 'i' line to the example: OLD: v=0 o=bob 280744730 28977631 IN IP4 host.example.com s= c=IN IP4 192.0.2.2 t=0 0 m=audio 6886 RTP/AVP 0 a=label:1 m=audio 22334 RTP/AVP 0 a=label:2 NEW v=0 o=bob 280744730 28977631 IN IP4 host.example.com s= i=A Seminar on the session description protocol c=IN IP4 192.0.2.2 t=0 0 m=audio 6886 RTP/AVP 0 a=label:1 m=audio 22334 RTP/AVP 0 a=label:2 Add to the beginning of Section 8 - Upon approval of this specification, IANA is requested to register the following new SDP attribute: